Automatically operated radio buoy



April 22, 1952 R- L. FREAS AUTOMATICALLY OPERATED RADIO BUOY 2SHEETS-SHEET 1 Filed June 18, 1948 INVENTOR.

I Lieu FIG. 4

R. L. FREAS 2,593,432

AUTOMATICALLY OPERATED RADIO BUOY '2 SHEETS-SHEET 2 April- 22,' 1952Filed June 18, 1948 IIIIIIIIIIIIIII Ill/Ill! IIIlIlII [III I- v IFatentecl Apr. 22, 1952 UNITED STATES PATENT GFFICE AUTOMATICALLYOPERATED RADIO BUQY Raymond Frees, Conshohocken, Pa. Application June18, 1948, Serial No. 33,835

(Granted under the act of March 3, 1883, as

' amended April so, 1928; 370 ,o. (1. 75:1)

Cl m This is a continuation in part of mycopendi'ng application SerialNo. 634,134, filed December 1Q, l945, for a Radio Float, which is nowabandoned.

This invention pertains to the art of signalling, and it comprisesapparatus operable automatically to send out signals. More particularly,the device of the invention is adapted to be thrown to the earth from amoving vehicle. When it reaches the earth the device conditions itselfautomatically for transmitting signals, and thereafter operates totransmit signals for a predetermined length of time.

For example, the device .of the disclosure is adapted to belaunched froman aircraft infiight when the aircraft is over a body of water, theobject being that the device will occupy a predetermined spot on thesurface ,of the water from which it sends out signals thatenable thelaunching craft to be located. The device descends to the surface of thewater with a minimum of deviation from a path that is verticallydownward from the launching craft, and theposition of the device on thewater surface is thereby located accurately. A particular weightdistribution of the components of the device contributes to this purposebeing attained.

, A parachute is embodied in the device, the parachute operating to openafter a predeterimined time interval following launching of the device,-so that ambient air. currents of the launching. craft do not interferewith accurate location of the device. The parachute enables the devicetostrike the water gently toavoidits injury from shock. When it reachesthe water, the device immediately operates to right itself into positionfor sending signals, anditcontains mechanism that works automatically toset up and operate the device as a signalling apparatus.

Signals are transmitted by the device for a predetermined time interval,after which the device operates todes lioy itself therebyto avoid itsgetting into the hands of persons unauthorized to have' it.

,A preferred embodiment of the invention is disclosed in theaccompanying drawings, to which attention is now directed for afullerunderstanding of the principles and operation thereof. In the drawings--Fig". 1 is an elevation of the device as it appears in condition forlaunching.

Fig. 2 shows the device in position to descend parachute borne,

3 shows the device in operating position for nd n s gna s powercomponent.

General arrangement of comp nemi The device of the disclosure comprisesabuoyancy component ll, Figs. 1,'2.and 3, and a component [2 thatconstitutes a ballast mass, the components II and I2 being positioned atop-v posite ends of the device, and being attached to each other bymeans-of an intermediate connecting'member I5.

As a signalling apparatus, the device comprises a radio transmittingset, which may embody any of a number of suitable radiotransmittercircuits. The circuit of the wiring diagram .in Fig. d'hasbeen employed and operated successfully. The disclosed circuit consistsof a transmitting or signalling component l1,'and a power supplycomponent or power pack l8. Radio-transmission circuits as such beingwell known in the art, detailed description of the elements of thecircuit shown in Fig. 4 is deemed unnecessary for'understanding thepresent invention. The important consideration is that the elementsoftheradio transmitter are so positioned "and assembled in the device as "toprovide a predetermined weight distribution, with the heavier piecesembodied in the ballast mass 12 and the lighter pieces cointainedin thebuoyancy component H.

The power component 1-8 embodies pieces that are comparatively heavy,such as the transformer t9, and the vibrator 2c. Theeleinents ot thetransmitting or signalling component H,;such, as the electron dischargetube 2|, and the various coils, resistors, and condensers shown in Figi, are pieces that are relatively light-weight; being so, it has beenfound 'e gpedient for-carry} s Outthe rpo of in ur ent-invention toembeds! e p e pa k It n the b last .2. and to contain most or all of theelements of the si n compo en 11 in the b qyanc c nponent.

The antenna 22 is of the extensible type. and

in collapsed condition it is no longer than the overall length of thestructure as illustrated in Fig. 1. The antenna 22 in collapsedcondition is housed in the connecting member I5, which accordingly ismade tubular to accommodate the antenna.

Ballast mass 12 As illustrated in Fig. 9, the ballast mass I2 is carriedor supported by the bracket 25 which embodies the nipple 23 to which theconnecting member I is attached. The connecting member I5 is preferablyconstructed of dielectric material, and in the disclosed embodimentconsists of a length of impregnated fiber tubing. The tube I5 isscrew-threaded at one end to receive the bushing 21 which has aninteriorly directedshoulder 28 and contains the washer 29 that seatsagainst the end of the tube I5. The sleeve 35 fits the tube I5exteriorly and provides added rigidity where it is attached to thesupport 25. The bushing 2'! and the reinforcing sleeve 33 are providedwith respective exteriorly directed flanges or shoulders 3I and 32,which are engaged by the coupling nut 33 which is threaded to the nipple26. The support bracket 25 thereby is rigidly attached to the tube I5 atits end.

The bracket 25 comprises the additional nipple 34 onthe side thereofopposite the nipple 25, the nipple 34 providing one attachment for theplate 35 to the bracket 25 by means of the nut 33, bolt 31 providing anadditional attachment.

The plate 35 serves as-a support or base for the power pack I8 which isembodied in the structure now to be described. The housing 38, Figs. 8and 9, is attached to the plate 35 by riveting or in any other suitablemanner, and contains the transformer I9 together with some of itsassociated elements. The housing 39 is also attached to the plate 35 ina similar manner, and serves as a mounting for the vibrator that issealed in its housing 140. The housings 45 and 39 are attached togetherby any suitable watertight connection 4i, preferably of rubber or thelike material, the connector 4| with housing 39 providing whatevercontainer space is needed for any other elements of the power pack thatare mounted on plate 35. The housings 38 and 39 are connected by anysuitablewatertight conduit (not shown), through which the electricalconductors extend between the various elements of the power pack I8which are contained in the several housings 35, 39, 45 and 4!. A closure42 of rubber or the like material is provided to seal the housing 38watertight, closure 42 being provided with integral grommets 43 throughwhich the leads 44 from the power pack I8 pass to other electricalcomponents of the device. The leads 44 are insulated with waterproofinsulation, and are preferably formed into a cable as shown, and thecable of leads 44 extends away from the power pack I8 through grommet 45seated in the plate 35.

Battery 46, Fig. 9 serves as a suitable generator of electrical energy,and is preferably of the type that is sensitized by water, whereby it isinactive in its original state but becomes activated by being placed inwater. Use of the Water sensitized battery 46 eliminates the need ofelectrical switches in the electrical circuit of the device. The battery43 comprises the bracing flange 4'! at its one end that fits around thetube I5, and at its other end the battery fits snugly around thecoupling nut 33 as shown. The battery 45 is attached to the bracket bymeans of the posts 48 and 49, respectively held by the bolt 31 and thescrew 50, and serves as additional ballast mass.

4 Buoyancy component 11 The buoyancy component II comprises the buoyancychamber 55, Fig. 7, which is preferably cylindrical and arranged to besupported by the tube I5, which extends concentrically lengthwisethereof. Tne buoyancy chamber 55 embodies an elongated container 58 ofcopper, brass or other suitable material, having a closure or lid 51 oflike material that is removably attached thereto by means of screwthreads 58 for example. For completing assembly of the device to make itready for its intended use, the threads 58 are preferably sealedwatertight when the lid 51 is attached to the container 55, brazingmaterial 53 or the like being employed for the purpose.

At one end of the buoyancy chamber 55, in the center of the lid 51 forexample, there is a collar 59 through which the tube I5 passes. Thegland nut 58, in the form of a sleeve, is provided to seal the tube I5exteriorly, and to prevent moisture from entering the buoyancy chamber55 between the tube I5 and the collar 59, packing 6| being included forthe purpose. The packing 5| is preferably a piece of tubing of rubber orthe like compressible material that presses tightly against the outerwall of the'tube I5 when the sleeve 5!] is tightened in the collar 59,the washer 52 of fiber or the like material being employed so that thepacking 5| Will not adhere to and turn with the sleeve 65. tion thebuoyancy chamber 55 at one of its ends is firmly attached to the tubeI5, the opposite end of 'the chamber 55 being attached to the end of thetube I5 remote from the ballast mass I8 by means of structure now to bedescribed. I

The metal sleeve 65 serves as an antenna cou pling in a manner to bedescribed hereinafter,

and is attached to the end of the tube I5 remote from the power pack I8,the tube I5 being screwthreaded at its end as shown for the purpose.This places the sleeve 55 proximate to the end of .the buoyancy chamber55 that embodies the to engage the bottom of, the container 56 and clampthe sleeve in rigid engagement with the incident end of .the chamber 55,washers 58 being employed to form a watertight seal of the hole inchamber 55 that receives attachment of the sleeve 65.

The described construction serves to hold the antenna housing tube I5concentric with the buoyancy chamber 55 and concentric with the antenna22. One end of the tube I5 bein attached to one end of the elongatedbuoyancy chamber 55 by means of the sleeve 65, the tube I5 extends awayfrom the attachment 65 through the chamber 55 lengthwise to the oppositeend thereof embodying the closure 57, the tube I5 being projectedtherebeyond. The ballast mass I2 is attached to the projected end oftube I5 in the manner hereinbefore described.

Antenna 22 The antenna 22, Figs. 5, 6 and 9 comprises a plurality ofmetallic tubes that are arranged telescopically, there being aninnermost interior tube 13, an outermost exterior tube 15, and as manyintermediate tubes I4 as are required to By means of the describedconstruc' product th csi ed'lc st of nna h n they are extend d "Theinterior tube 13, and each of the intermediate tubes 1-4, is providednear its base end with a pair ofannular external ridges 11, that arespaced apart lengthwise of the tube, the ridges 1-1being-preferably-formed bycrimping the tubing circumferentially. At thevertex of -each intermediate tube 14, and of the exterior-tube 15,;thereis arranged around the periphery-of the tube a set of longitudinallydisposed internal ridges l8. and these serve to taper the vertex of eachlarger tube 14, 75 to fit the external =cireumference of its nextadjacent smaller tube 13 or 14. Each larger tube 14,15 is provided withasimilar set of longitudinal ridges Z9 spaced away from its vertex, thesetofridges 19 being spaced apart-from the sets of ridges 18 as shown.The sets of ridges l8 and 19, also, are preferablyformed bycrimpingthetubing. The lengthwise spacing between sets of ridges 18 and 19 is madeto fit over the "spaced apart annular ridges ll of respectivelynextsmaller tubes. The described construction isa convenient expedientfor sealing eachsmaller tube 13 or 14 within its next larger neighboringtube 14 or 15, and for providing bearing surface of limited extentbetween adjacent tubes to reduce friction when the tubes are'slidlengthwise of each other to extend the antenna 22. When the antenna 22is in extended condition. the pairof annular ridges 11 at the base ofeach smaller tube 13 and 14 lodges between the sets of longitudinalridges i8 and 1'9 'at the vertex of its next larger tube i l or E5, inthe mannerillustrated in Fig. 6, and this serves to prevent'collapseofthe erected antenna 22. The seals formed by the annular ridges 17 andthe longitudinal ridges l8 and 19 between tubes 13 and 14 and theirrespective next larger tubes M or- 15. is sufiicient to preventexcessive escape of pressure fluid from within the expanding fluidchamber formed by ,the tubes T3, M and .75.

The butt end of the exterior tube 15 abuts against the gasket 29, whichis backed by the in-.. teriorly directed shoulder 28 of the bushing 2?.

Near its butt end, the exterior tube 15 is pro vided with the retainingmember 86, that com prises a plunger 8|, Fig. 6, movable. in the barrel82, the plunger 8.! and barrel 82 being urged radially outwardly fromeach other by the spring 83. Theplunger 8.1 comprises the abutment head8.4, and the barrel 8.2 comprises a companion op-.. posite abutment end85. The abutment head '84 and the abutment end 85 ride in springepressedengagement with the. inside wall of the tube l5 along diametricallyopposite cylinder-elements while the exterior antenna. tube 15 is being.projected lengthwise of the housing tube IE to erect the. antenna 22.There is also an annular external ridge 86 near the butt end of theexterior antenna tube I5 that is formed similar to ridges ii, the ridge86 being spaced away from the retain-. ing-mem-ber Bil lengthwise of thetube 15. The ridge 86 rides on the inside-surface of the tube l5.

The bore of the sleeve 65 at its extremity is of slightly lessdiameterthan theinternal diameter of the tube 15-, and it is also smaller thanthe outside diameter of ridge 86, the bore of the sleeve 6-5 beingstepped as shown'in Figs. '6 and .7 to provide the recess 81 where it isjoined to the end of the tube [5. When the exterior antenna tube 15 isinfully extended position, the annular ridge 86 thereof and the retainingmember 80 become confined in the recess 81', in the manner 6 firmly inerected position and to prevent itscollapse. The spring clip-88 isattachedto the sleeve exteriorly to provide anantenna-couplingtem minal,the antenna circuit being from tubes 13, 1.4, 15 through the retainingmember to the sleeve .65 and terminal 88, and being insulated fromground by means of fiber tube l5 and .the clampin discs 66 and 6.7.

The interior tube 13.01 the antennais provided at its .vertex with .abutton 16 that .closes :the antenna 22 at its .tip, and alsoconstitutesan abutmentmember thatseryes ina manner to be describedhereinafter.

.The closure...9,8 for. the antenna-housin tubenlli cniinestheantenna Z2thereinincollapsedconitionflheclcsure 9.0. accordingto the. p efer edconstruction shown...ccm risesadiscsl of blo tine pa er .orthe likemateri l. which is re-v infcmed by means of a disc .32 of :metal or thelike rigid material, the discs .91 and .92 being attached to each otherby means of the nret 93. The cap .94 screws onto the end of thesleevea65, thereby en agin the blotting-paper .disc. .91. The metal disc.92 .is. large enough to. coyer the aperture through 6.5, but is smallenough td-pass freely through the aperture of.cap-.94..

The. closure Si! confines theantennafl -.within t e tube 15 duringstorage. and .until the device of the. invention is placed in .use. The.closure 90 projects downwardly as se n in Fig:. :.2; when thedeyicestrikes thewater. and the metal. disc 92 presses against. the end ofsleeve titoreinforce the. blotting-paper disc .91 a ainst collapsing derthe pressure of the water. and to prevent water from entering. the tube.l5. Water is absorbed. by the blottin p per of. disc .91, hi h th re ybe ins to disintegrate. and. lose its strength. When the device becomes.rightedtin the water, the disc 9| having lost, its strength ofiersineffectual resistance to the tubes. 1.3,. 1.4 and 15 being extended,and the blotting paper is sheared at the periphery of the aperturethrough cap 94 b the button 16 pressin against it to erect the antenna22., Thexantenna 22 is thereby extended out of theend of the tube l5,andbeyond the end of the, buoyancy chamber 5.5 th marrner illustrated inFig. 3.

Antenna erecting drive The m c an sm, for erec i g the antenna .i

illustrated generall at v and c mprises a member that-embodies acombustion chamber I00 and s a tache at its. o e. nd to the nipple 3 ofthe brack t 25-. A its hcr, n th c m.- bu io hamb H10 compri s. acompartm nt that contains a predetermined quantity of suitable explosiveIQI confined between partitioning discs I02 and H13 of Celluloid or thelike combustible material. The-end of combustion chamber I00 thatcontains explosive lili also has ate tached thereto the igniter ordetonator- 10-4 in the form of a modified automotive spark plug, themodification comprising an electrical heating coil I05 connected betweenthe positive and ground terminals. The space. adjacent to the Celluloiddisc I02 that is occupied by the heating coil I05 also contains anexplosive 106. Under preferred practice, the explosive It! consists ofslow-burning granulated powder that has-a'high volumetric expansion, andthe explosive lfltconsists of black powder that detonates when sub-.jected to a temperature lower than is required for detonating explosiveI0 I.

The baflle l 01 is positioned between the com illustrated in Fig. 6,--to hold the antenna 25 if! bustion chamber I00 and the nipple 3A withaiieaeise.

washers 'I I2 serving as a seal. Aperture I08 in baflie I01 constitutesa constricted passage for gas generated by the explosives IOI and I06from the combustion chamber I into the cavity I09 of nipple 34. PassageIIO permits the expanding gases to enter the cavity I I I of nipple 20from the cavity I09, and from the cavity III the gases enter thecylinder of tube I through the aperture of bushing 21 formed by theshoulder 28.

An electrical lead II5, which is covered with waterproof insulation,connects the heating coil I05 in circuit with thebattery 40, as seen inthe wiring diagram of Fig. 4. Housing H6 is provided toenclose andprotect the igniter I04. An aperture H1 in the housing II6 serves as aconduit forthe leadll I5 to the exterior 'of the -housing '6; forconnecting ignitor I04 with battery 46.: The housing II6 also includesthe suspension eye II8, thepurpose of which will be described more fullyhereinafter. I 1

When the battery 46 becomes energized by 'con-' tactiwith water, itheats the coil I05 until the temperature thereof becomes high enough. toignite the black powder I00 which then detonates the slow burning powderIOI. Gas is thereby generated, which is expanded into the cavity I09through the aperture I08 of bafile I01, andfrom the cavity I09 intocavity I I I through the-passage H0. The expanding gases then enter thetube I5 through bushing 21, and they operate intube I5 to drive theseveral antenna tubes 13,10 and into extended position to erect theantenna 2-2. Expansion of the gases in the combustion chamber I00 intothe cylinder of tube I5 through the intermediate cavities I09 and IIIproduces a'less violent but more prolonged and'persistentactua-. tion ofthe antenna tubes 13, 14 and "65 to erect the antenna 22.

The expanding gases act against'the end of iriternal tube 13 that isclosed by button '16, which presses against the water weakened disc 9IIof blotting paper, thereby shearing disc QI and driving it and attacheddisc 92 through the aper tured cap 94. Internal tube 13, and eachintermediate tube 14 travels to project beyond the vertex of its nextlarger'tube 14 or 15 until its pair of annular ridges I'I lodges betweenthe. sets 18 and 19 of lengthwise ridges at the vertex of its nextlarger tube 14 or 15. In a similar manner, the annular ridge 85 of theexterior tube 15 together with the retaining member 00are guided alongthe inside wall of tube I5 until they lodge in the recess 01 of thesleeve 05,- and when this is accomplished the retaining member 00 servesas an electrical conductor betweenthe antenna 22 and its terminal 88.

Signalling component:

fore mounted to be supported by the tube I5 inslde'chamber 55, chassisI20 beingprovided for the purpose.

The chassis I20, according to preferred construction, comprises a discthat fits loosely in and is easily inserted into the container; 56,. vThe.

chassis 120 is rigidly attached-t0 acentral bushing I2I that fits aroundthe tube I5, a companion sleeve I22 being provided that also fitsexteriorly of the tube I5 and is threaded into the bushing I2 I.The-packing 23 of rubber or the like compressible material is enclosedin the bushing I2I to'press into firm frictional engagement with theexterior wall ofthe tube I5 when subjected to. compression by the sleeveI22 being tightened in the bushing I2I, and the washer I24 is includedin the structure to prevent the packing from twisting by frictionalengagement with the sleeve I22.

The coil illustrated generally at I25 in Fig. '1, which may for exampleconstitute the radio frequency inductor coil I25 in Fig. 4, is supportedby the chassis I20 on the spacer sleeve I26 that bears against bushingI2I and serves to locate. coil I25 lengthwise of the tube I5. The coilI25 includes the main winding I21, consisting of a predeterminednumberof turns of wire held in position'by sets of opposed inside and outsidestaves I28 and I29 respectively, the companion inside and outside stavesbeing adhered or otherwise attached together, and being adhered orotherwise attached at their ends to the opposite heads I30 of dielectricmaterial. The nut I31. by engagement with the spacer sleeve I32, pressesthe winding I21 firmly against the sleeve in and through sleeve I25against the bushing I2I, byscrew threaded engagement of the nut I3I withthe tube I5 as shown;

The tuning coil or winding I33 is a continuation of 0011- I25 and isconnected in series withthe main winding I21. Winding I33 comprises apredeterminednumber of turns of wire wound on the spool or tube I30 ofdielectric material; rings I of dielectric material being adhered orotherwiseattached to the tube I34 to complete the assembly of windingI33. The winding I33 is attached to and carried by the chassis I20 bymeans of the rings I35 being adhered or other: wise attached to one ofthe external staves. I29 of the assembly of winding I21.

The permeability core I36 is adjustably mov able into differentpositions lengthwise in the winding I33 for tuning 0011 I25 toa'predetermined desired Wave length, and for making thedesired antennamatching adjustment. Core I36 s is carried by the chassis I20 and issupported by. the rod I31 that is attached to the chassis I20 1 rod I39and through the intermediate insulator I 20. The core I36 is slotted-atMI toreceivea pose to enable a screwdriver or the like tool to: beinserted into chamber through the hole;

that-is closed by plug I 42.

Other elements of they signalling component II that appear in the wiringdiagram of Fig. 4 are,

preferably-mounted on the chassis I20, but the manner of mounting theseelements can follow well-known prior-art practice, and requires nofurther detailed description herein.

Electrical connections between, parts of the power pack I8 embodied inthe ballast mass I2 and parts of the signallingcomponent I1 em-- bodiedn h r u yan y c m on tlz a e made.

by-ineans-of the leads 44 of the formed cable, the leads being insulatedeach with a'waterprocf jacket. The leads 44 enter the buoyancy chamber55 through the watertight grommet or fitting I43, and comprise theterminals I44; Electrical connections within the chamber 55 between theterminals I44 and parts of the transmission component I1 can be madeinany suitable manner understood by persons skilled intheart-fromthewiringdiagram of Fig. 4, and this requiresno further detaileddescription'herein;

- self-seaming device It is desirable that the sigi'iallin-g' apparatusof the present invention be kept out of the hands of unauthorizedpersons, and for this purpose the device of the inventionis adapted todestroy itself after'it has servedits purpose of sending out signals.Mechanism that destroys the deiiice'is embodied in the time-delayscuttlingval-ve, illu'str'ated generally at I50, Fig". 7.

The scuttlingi valve I50 comprises a container or cup II, Whichisattached rimdownwardly by brazing or other suitable means to the insideof the lid or closure 51 that forms the bottom of the buoyancy chamber55 when the device is afloat on a body of waters A second cup I52 issimilarly attached to the cup I5I, at a position thereof away from itsattachment to the closure 51, and a third cup I53 is attached to the cupI52 in a similar manner. As many cups I5I, I 52, I53, eto., are providedas are required to afford the desired time-delay for scuttling thedevice. The cups I5I, I52, I53, constitute a series of con tainer'sthrough which water must pass to enter the buoyancy cham-ber55, andeachcup has an aperture I54 in its partitioning surface thatcoinrnunicates with the next adjacent container in the series, theaperture IE4 or the last cup I 55 in the series communicating with thebuoyancy chamber 55. The surface of each cup I5I, I52, I53 that containsthe aperture I54 is depressed in a direction that is downward whentheapparatus floats on a body of water, whereby the a erture I54 dipsdownwardly towards the sur face of water contained in its incident cup.The size of each aperture I54 is predetermined to pro vide the requiredtime metering for the desired time-delay.

Water passes from outside the buoyancy chamber 55 through the lid 51into the first cup I 5I of the series, the, passage, being through the,fitting I55, which is attached to the lid 51 by means of the grommetorgasket I55 of rubber orthe like resilient material. Water enters thecen-' tral bore I51 of the fitting I5 5; through the constricted portI58 and the passage for water to enter port I58 comprises the annulargroove I59 that is narrower than the opening of port I58 but has agreater fiow area. This construction operates to filter foreign solidmatter out of the water that flows through the fitting I55 and prevents;it from entering the port I58. The annular groove I59 is formedby'the-overhang-ing apron of the cap I55.

From the time the apparatus enters the water, any water that flowsthrough fitting I55 is trapped by the cupsISI, I52 and- I53 and does notenter the chamber 55 until the cups are filled. After the apparatustakes position on the water surface for sending signals, with theballast mass I2 directed downwardly, the closure 51 isat the bottom-ofcham-ber55 and underwater. Water flows into the cup I5Ithrough-the'fitting I55;

any air in the cup I5I is expelled into cup I52 10 through its apertureI54; This continues until the water level inthe cup I5I reaches thelevel of the aperture I54 therein, when water flows from cup I5I intocup I52 to fill it and overflow into cup I53 until it becomes full.- Airfrom the cups being expelled through apertures I54 into chamber 55. Whenall the cups I5I; I52; I53 become full, water flows into the buoyancychamber 55, which by that time is calculated to have served its purposeof sending a series of signals, the flow of water into buoyancy chamber55 continuing until it becomes water-logged and sinks.

Air is driven out of the buoyancy chamber 55 by water entering throughthe scuttling valve I50, and the air-escape valve I5I is provided forthe purpose. The air escapevalve I6I comprises the fitting I62, which isattached to the buoyancy chamber 55at its top by means of the grommet orgasket I53, in a manner similarto the fitting I55. The fitting I62 alsoincludes the central bore I54, and the outlet port I65 that isconstricted in a manner similar to port I58. Port I55 communicates withthe annular groove I55 formed by the overhanging apron of the; cap I61.The annular groove I66 is narrower than the port I65 and operates tofilter forign'niatter out of any water that enters the chamber 55through the fitting I62.

When the device strikes the water, the bottoin of the container 55 whichembodies the fitting I52 isdir'ected downwardly, and it is submergeduntil the apparatus rights itself for sending sig' nals'. Water thatpasses through the fitting I62 is trapped in the baffle cup I63 that isattached to'the grommet I63 inthe manner shown. The aperture I69 throughthe cup I58 is in the entrant bottoin'there'of as shown so that; whenthe apparatus is" righted forseridihg signals, the aperture I69 is'positioned above the level of any water that may have become trapped inthe cup I58. The water trapping cup I68 prevents water from getting intodamaging contact with the electrical apparatus housed in the cham er 55,and permits the escape of air from the chamber 55 that is displaced bywater entering the' s'cuttling vaive I50.

Parachute pack Parachute I15 is attached to the apparatus at the ballastm'ass' end I2 thereof, as illustrated Fig 2. whereby the apparatus issuspended dur ing its descent with its center of gravity locate near itspoint orsuppor t, The load carrying web I16 of the parachute I15 islashed or tied tome sus ension eye He of theig'niter housing H6,parachute I15 being attached to the load c rry ing web I15 by means ofthe shroud lines I11.

Cover I18 is provided, which in the preferred disclosed embodimentcomprises a container of canvas or other suitableclothh The cover I18 isattached to the parachute I 15 at its top by means of the cord or lineI19, the tensile strength of cord I19 being sufiicient to extend theparachute from it's folded to its expanded condition. but being so lowthat it breaks readilyli nderthe weight of the apparatus of theinvention. The lanyardor lash I85 at one of its ends is attached to thecover I 18 at its top as shown, and is strong is thrown from the craft,it falls to a position out of range of ambient air currents thereofuntil the lash I80 is jerked by the weight of the apparatus.

When the apparatus is in assembled condition and ready for launching,the parachute I15 is folded in any suitable manner and packed around theelements of the ballast mass I2 that are mounted on plate 35. The coverI18 is positioned over the folded parachute I15 with the line or cordI19 also enclosed in it, and cover I18 is attached at its hem or edge tothe plate 35 by means of ties I8I that are passed through holes I 02arranged circumferentially of the plate 35 near its edge. The tensilestrength of the ties I8I is so low that they are readily torn whensubjected to the weight of the apparatus.

Operation The apparatus can be launched from an aircraft in flight inany suitable manner, preferred practice being to adapt the device to befired from a launching gun for signal flares or the like, such as are incommon use on military aircraft. The device comprises a compact mass,and when it is launched it falls away from the aircraft in compactcondition a distance determined by the length of the lanyard or lashI80. When the device has fallen the predetermined desired distancethelash I80 is drawn taut, and the Weight of the apparatus applies shocktension that tears the ties IBI. The cover I18 is thereby pulled awayfrom the plate 35, and the apparatus continues to fall freely. The coverI18 thereby pulls on cord I19 and extends the parachute I15. When theparachute I15 becomes fully extended in condition to become airborne,the weight of the apparatus again jerks the lash I80 and the cord orline I19 is thereby torn under the weight of the apparatus. Theparachute I15 is now in extended condition ready to become airborne. Thelanyard I80, with the cover I18 attached to its terminal end, continuesto be attached to the aircraft.

It will be noted that the ballast mass I2 is disposed upwardly while thedevice descends under parachute support, positioning the center ofgravity of the apparatus close to the parachute 115. Accordingly,atmospheric air currents are less able to divert the apparatus fromdirect downward travel, and the apparatus therefore descends to theearth with minimum deviation from a vertical path. Location of theapparatus on the surface is accordingly more accurately de terminablewith reference to the position of the launching craft.

When the device strikes the water, it first submerges, due to themomentum of its fall, but the buoyancy chamber 55 comes to the surfacequickly, and the ballast mass I2 is suspended downwardly as illustratedin Fig. 3. The water begins to operate immediately to activate thebattery 46, and when it has been activated sufficiently to supply therequired electrical power,

it operates to heat the heating element I of only restricted flow intocavity I08 being allowed through constrictedpassage I00. In a similarmanner, only restricted flow ofgases'from cavity I09 to cavity III thatjoins through bushing" 21 with the tube I5 is permitted throughtheconstricted passage I I0. Thus, in theirpassage from the combustionchamber I00 to the tube I5, the gases go through two stages of pressurereduction in the respective expansion chamber I09 and II I, providing amore uniform, steady and continuous supply of pressure fluid thatoperates in tube I5 to erect the antenna 22 than would be supplied bythe explosive .directly. r

Th 'expanding gases. that enter the tube I5 operate to actuatethe'interior tube 13 and each intermediate tube 14 lengthwise of itsrespective next larger tube 1 3 or 15, andoperateto actuate the exteriortube 15 lengthwise of tube I5, until all the pairs .of annular ridges11v lodge between the sets of longitudinal ridges 18 and 19 of nextlarger tubes 14 or 15, and the'annular ridge ,85 with the retainingmember 00 of exterior tube 15 lodge in the recess 81 of the sleeve 65. j

The heat of combustion of the explosives IOI and I05 operates to destroythe heating coil I05, opening the electrical circuit thereof, andneedless consumption of electrical energy is thereby avoided.

The activated battery 46 also operates to supply electrical energy tothe radio transmitter constituting components I1 and I8, in a mannerthat will be clear to .persons skilled in the art from the illustrationof Fig. 4. Radio signalsare thereby transmitted at a predetermined andknown wave length and frequency, which can be picked up by any suitablereceiving set. Operation of the radio transmitter, and also of theantenna erecting mechanism, is instituted by the battery 45 becomingactivated when it enters the water, and the need of electrical switchesis thereby entirely eliminated from the apparatus.

The signalling apparatus of the disclosure has a number of advantageoususes. For example, if a pilot is flying a planned course over a largebody of water that lacks landmarks, and he desires to determine if andto what extent he is being blown off course by adverse winds, bylaunching a signalling apparatus embodying the present invention he isenabled to receive the signals therefrom through his direction finder.He thereby determines his direction of flight with reference to thesignalling apparatus he has placed on the water, and he ca'n interpretthis information with reference to his apparent course as determined bythe trim of the craft, to thereby ascertain the amount that the aircraftis drifting from its planned direction of flight.

After the device of the invention has served its purpose to send out thedesired signals, it automatically destroys itself after a predeterminedtime interval by means of the scuttling valve I50.

The structure of the drawing constitutes one practical embodiment oftheinvention,-which can be modified in a number of ways without departingfrom the scope and spirit of the in vention. Accordingly, the inventionis not limited to the specific structure disclosed, but scope of theinvention is determined by the accompanying claims. 7

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

Whatiscflaimedis:

I. In a signalling device, a. radio transmitter including an antenna, atube supporting the antenna, a'buoyancychamber attached to. the tubeattone end thereof, a support attached to the tube at the other endthereof and carrying components of the transmitter that embody the majorportion of-its mass, the support with the transmitter components carriedthereby constituting a ballast mass.

2'. Ina signalling device, a radio transmitter including an antenna, atube supporting the antenna, a buoyancy chamber attached to the tube atone end thereof, a support attached to the tube at the other-end thereofand carrying components of the transmitter that embody the major portionof the mass thereof, the support with the transmitter components carriedthereby constituting aballastmass, a parachute attached to the device atthe end thereof embodying the ballastmass.

3. Ina signalling device, aradio transmitter comprising a power pack andan antenna, a tube supporting the antenna, a buoyancy chamber at tachedto the tube at its one end, the power pack being attached to the tube atits other end and serving as ballast mass.

4'. In a signalling device as defined in claim 5, the transmittingcomponent being contained in thebu'oyancy chamber.

5; In a signalling device as defined in claim 5, the transmittingcomponent being contained in the buoyancy chamber and. electricallyshielded thereby;

6, In a. signalling device, a radio transmitter comprising a power pack,an antenna and an electrical energy'generator, a tube supporting theantenna, a buoyancy chamber attached to the tube atits one end,the powerpack and the generatorbeing attached to the tube at its other end andserving as ballast mass.

7. In a signalling device, a radio transmitter including an antenna andan electrical energy generator, a tube supporting the antenna, anelongated buoyancy chamber attached to the tube at its one end, the tubeextending from the attachment through the buoyancy chamber lengthwisethereof and projecting therebeyond, the electrical energy generatorbeing attached to the projecting end of the tube and serving as Ii'ng'from' the attachment through the buoyancy chamber lengthwisethereof and projecting therebeyond, the power pack and the electricalenergy generator being attached to the projecting end of the tube andserving as ballast mass.

9. In a signalling device, a radio transmitter tenna, .an. elongatedbuoyancy chamber attachedto the tube at its one end, the tube extendingfrom the attachment through the buoyancy chamber lengthwise thereof andprojectingtherebeyond, an antenna erecting device attached to andoperable at the projecting end of the tube to actuate the antenna out ofthe end of the tube attachedto the buoyancy chamber and to project theantenna beyond the buoyancy chamber.

11,. In a. signalling device, a radio transmitter comprising an antennaand an electrical energy generator, a tube containing the antenna, abuoy ancy chamber. attached to thetube at its one end, the: electricalenergy generator being attachedto the tube at its other end and servingas ballast mass, an antenna erecting device operable at the end oi thetube to which the generator is attached and. comprising an explosive, adetonator operable electrically from the electrical energy generator,and a passage from the explosive to the end of the tube to which thegenerator is attached for the gases derived from the explosive, wherebythe antenna is erectedby'being projected out of the end of the tubeattached to the buoyancy chamber.

12. In a signalling device, a radio transmitter comprising components ofheavier and lighter weight respectively and an extensible antenna, atube containing the antenna, an elongated buoyancy chamber attached tothe tube at its one end, the tube extending from its attachment throughthe buoyancy chamber lengthwise thereof and therebeyond, the heaviercomponents of the radio transmitter being attached to the tubeattheprojecting' end thereof. and serving as ballast mass.

13'. In asignalling device as defined in claim 12, the lightercomponents of the radio transmitter being housed in the buoyancychamber.

14. In a signalling device as defined in claim 12, an antenna erectingdevice operable to erect the antenna by projecting it out of the end ofthe tube attached to the buoyancy chamber.

15. In a signalling device, a radio transmitter comprising components ofheavier and lighter weight respectively, an extensible antenna and abattery that is activated by contact with water, a tube containing theantenna in collapsed condition, an elongated buoyancy chamber attachedto the tube at one end thereof, the tube extending from the attachmentthrough the buoyancy chamber lengthwise thereof and projectingtherebeyond, the heavier components of the radio transmitter and thebattery being" at,-

tached to the tube at the projecting end thereof and serving as ballastmass, an electrically operable antenna-erecting device operable to erectthe antenna by projecting it out of the end of the tube attached to thebuoyancy chamber, the battery operating to supply energy to the radiotransmitter and to the antenna erecting device by the signalling devicebeing placed in water.

16.- In asignalling device, a radio transmitter comprising components ofheavier and lighter weight respectively, an extensible antenna; and anelectrical energy generator, a tube containing the antenna in collapsedcondition, an elongated buoyancy chamber attached to the tube at its oneend, the tube extending from the attachment through the buoyancy chamberlengthwise thereof and projecting'therebe'yond, the heavier componentsof the transmitter and the generatorbeing attached to the tube at theprojectingend projectingit outoi the end of the :tube attache to thebuoyancy chamber.

17. In a signalling device as defined in claim 16, the electrical energygenerator comprising a batterythat-is activated by contact with water.'18. In a signalling device, a radio transmitter comprising heavier andlighter weight components and including an extensible antenna, a tubecontaining the antenna, abuoyancy chamber attached to the tube at itsone end, the heavier components of the transmitter being attached to thetube at its other end and serving as ballast mass, a closure for thetube at the end thereof attached to the buoyancy chamber and beingdestructible by contact with water, an antenna erecting instrumentalityoperable when the device is placed in Water to erect the antenna by.projecting it out of theend of the tube that is attached to the buoyancychamber, a parachute for the signalling device attached thereto at theend embodying the ballast mass. 19. A device for transmitting signalscomprising, an electrical energy generator and a radio transmitterincluding an antenna, a tube housing the antenna, a buoyancy chamberattached to the tube at its one end, the heavier components of thetransmitter being attached to the tube at its other end and serving asballast mass, a parachute attached to the device at the end thereof.

embodying the ballast mass.

20. A device for transmitting signals comprising an electrical energygenerator and a radio transmitter including an antenna, a tube housingthe antenna, a buoyancy chamber attached to thetube at its one end, asupport bracket attached to the tube at its other end, the generatorand'the heavier components of the transmitter being attached to thebracket and serving as ballast mass, a parachute attached to the deviceat the end thereof embodying the bracket.

21. A device for transmitting signals comprising an electrical energygenerator and a radio transmitter including an extensible antenna, atube'housing the antenna, a buoyancy chamber attached to the tube at itsone end, a support bracket attached to the tube at its other end,mechanismoperable by the device contacting water to erect the antenna byprojecting it out of the end of the tube that is attached to thebuoyancy'chamber, the generator and the antenna erecting mechanism beingattached to the bracket and serving as ballast mass, a parachuteattached to the device at the end thereof embodying the bracket. j 22.In" a device for transmitting signals, an electrical energy generatorand a radio transmitter including an antenna, a tube housing theantenna, mechanism operable by the device contacting water to erect theantenna by projecting it out of one end of the tube, a buoyancy chamberdisposed around the tube and extending lengthwise thereof withone of itsends positioned near theend .of the tube from which the antenna isadapted to be projected, a support bracket attached to the other end ofthe tube, the generator and the antenna erecting mechanism beingattached to the bracket and serving as ballast mass, a parachuteattached to the device at the end thereof embodying the bracket.

23. In a portable radio transmitter, an extensible antenna comprising aset of tubes fitted one within the other, a plurality of annular groovesnear the base end of each smaller tube and spaced apart lengthwisethereof, a set of longitudinal grooves arranged peripherally of eachnext larger tube and disposed at the vertex thereof, asimilarset of.longitudinal grooves-near the vertex of each next larger tube anddisposed spaced apart from the set of grooves at the vertex, the twosets of longitudinal grooves in each larger tube being spaced apart anamount-that encompasses the spaced apart annular grooves ofthenextsmaller tube, and antenna erecting mechanism operable to projecteach smaller tube out of the vertex end of its next larger tube with-itsannular grooves lodged between the spaced-apart sets of longitudinalgrooves thereof.

, 24. An extensible antenna comprising a set of tubes fitting one withinanother, a plurality of annular grooves near the base end of eachsmaller tube and spaced apart lengthwise thereof a set of longitudinalgrooves arranged peripherallyof each next larger tube and disposed atthe vertex thereof, a similar set of longitudinal grooves near thevertex of each next larger tube and disposed spaced apart from the setof longitudinal grooves at the vertex, the two sets of-longitudinalgrooves in each larger tube being spaced apart an amount thatencompasses the spaced apart annular grooves of the next smaller tube.

25. An extensible antenna comprising a set' of metallic tubes fittingone within another and arranged telescopically, a tube of dielectricmaterial housing the'metallic tubes in collapsed condition, a metallicsleeve attached to the outward end of the dielectric tube and comprisinga stepped bore that provides an annular recess. at the end of thedielectric tube of larger diameter than the inside diameter of thedielectric tube, an electrical terminal exteriorly of the sleeve, anelectrical conductor at the base end ofthe largest metallic tubepressing resiliently outwardly against the inside wall of the dielectrictube, the electrical conductor seating in the recess in electricalcontact with the sleeve when the an-' tenna is erected and projectingout of the end of the dielectric tube.

26. In signalling apparatus adapted to be launchedirom an aircraft inflight to operate on the surface of a body of water, a buoyancy chamberat one end thereof, a ballast mass at the other end thereof, a parachuteattached to the appa-r ratus by being attached to the ballast massthereof, a parachute cover enclosingthe parachute in folded condition, aparachute extending line between the cover and the parachute and havinginsufiicient strength to support the weight of the apparatus, tiesattaching .thecover to the apparatus with the parachutein foldedcondition en.- closed therein, the ties having insufficient strength tosupport the weight of the apparatus, a launching line of greaterstrength than either the parachute extending line or the ties, thelaunching line having a predetermined length and being attached at oneof its ends to the cover exteriorly thereof.

2'7. In a signalling apparatus adapted to be launched from an aircraftin flight, a parachute pack comprising aparachute attached to theapparatus, a cover for the parachute enclosing it in folded condition, aparachute-extending lin at taching the cover to the parachute and havinginsufi-lcient strength to support the Weight of the apparatus, tiesholding the cover in parachute enclosing position and havinginsufiicient strength to support the weight of the apparatus, alaunching line of predetermined length and being attached at its one endto the cover, the line being attachable to the aircraft at its otherend, the

17 launching line having greater strength than either the ties or theparachute-extending line.

28. For-launching a load from an aircraft in flight, a parachute packcomprising a parachute attached to the load to carry it, a coverenclosing the parachute in folded condition, ties attaching theparachute cover to the load with the parachute held in folded conditionagainst the load, the ties having insufiicient strength to carry theweight of the load, a parachute-extendingline attaching the cover to theparachute and having insufiicient strength to support the weight.

of the load but suflicient strength to extend the parachute, .alaunching line of predetermined length and being attached at its one endto the cover, and being attachable to the aircraft at its other end, thelaunching line having greater strength than either the ties or theparachute extending line.

RAYMOND L. FREAS.

REFERENCES CITED The following references are of record in the file ofthis patent:

